Latch knob and locking means therefor



Sept. 30, 1958 A. ERKKILA LATCH mos AND LOGKING ms Tl-BEREFOR Fileq Nov. 15, 1954 2 Sheets-Sheet 1 INVENTOR 097165;!) .Er/akila fiTTORNEY 6 7. 5 5. mo w :1 F i w w w w Sept. 30, 1958 A. ERKKILA LATCH mos AND LOCKING MEANS THEREFOR 2 Sheets-Sheet 2 Filed Nov. 15, 1954 INVENTOB flndrew ,Erlvkzla ATTORNEY United States Patent LATH xNoB AND rocxnso MEANS rnnn'aron Andrew Erkkila, Fitchburg, Mass, assignor to Independent Lock Company, Fitchburg, Mass, a corporation of Massachusetts Application November 15, 1954, Serial No. 468,649

6 Claims. (Cl. 292-348) This invention relates to screen door latch sets, to the spindle knob locking assembly thereof and to locking means therefor.

My invention is a continuation in part of my application Serial No. 376,675, filed August 26, 1953, now Patent No. 2,795,446, dated June 11, 1957, entitled Narrow Frame Screen Door Latch and Method of Mounting the Same.

My invention more specifically concerns itself with, and it is an object thereof to provide in a latch spindle assembly for a latch set to be used, for example, on screen doors, spindle and knob assembly means which may be installed quickly and efficiently and to present, particularly to the exterior turn knob of this assembly, a tamper-proof construction, and also assure a minimum of maintenance and adjustment problems.

My invention has for its object the provision of a spindle and knob keying engagement for locking these two elements to each other and to the escutcheon serving as a bearing for the spindle knob which is attachable without special tools and is tamper-proof, to resist displacement of the connection between the spindle and knob and the latch assembly.

Still more particularly, this invention relates to and has as its object the provision of simple and low cost yet rugged spindle locking means, useful in connection with latches employed on door frames, such as screen doors or storm doors.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, I make reference to the accompanying drawing, forming a part hereof, in which- Figure 1 is a sectional view of a latch in accordance with my invention, mounted on a metal stile door;

Figure 2 is a magnified section taken on the line 22 of Figure 1;

Figure 3 is a fragmentary section taken on the line 33 of Figure 2;

Figure 4 is a fragmentary section to show an intermediate assembly position in a plane corresponding to Figure 1;

Figure 5 is a view similar to Figure 4 in the assembled position;

Figure 6 is a section taken on the line 66 of Figure 5;

Figure 7 is a section taken on the line 77 of Figure 5.

Making reference to the drawing, I have illustrated my invention in connection with a metal door 19, a fragment of which is shown fitting a tubular stile 11. Such frames as described in my prior mentioned application may be of sheet metal, preferably extruded aluminum, serving the double purpose of a storm door during the winter and a screen door during the summer.

The stile 11 has a closure edge 12, terminating in a channel 13. A latch casing 14 extends through the closure edge 12 to seat a latch flange 15 in the channel 13 and mount the latch bolt 16 for projecting into the frame strike aperture 171:. The latch casing 14 is held in the hollow stile 11 by the support rod 17, extending through the aperture 18 and through which the camming spindle 19 extends. The outside end 20 of the spindle projects through the outside escutcheon 21 upon which is mounted the outside thimble 22. The thimble 22 has a flange 23, providing an annular groove 24, into which the lip 25 of the escutcheon plate extends for rotationally mounting the thimble 22 with respect thereto. The thimble likewise provides a throat 25, through which the spindle extends. It is upon the end 20 that the knob member 27 is mounted.

The knob is hollow comprising a shell member and is fitted with a shank 28, into which a knob insert 29 is extended. The knob insert 29 is cut with a keyway 30 forming a socket of generally square cross-section, to receive the spindle 20 extending therethrough. The keyways 30, at its forward end 31, closely fits the contour of the spindle 20 adjacent its front wall 32.

One wall 33 of the keyway is cut with a slot 34, which is angularly directed toward the leading end wall 35 adjacent the flange 36, which is turned in over the knob insert. The knob insert 29 is formed with a tapered boring 37 into which a portion of the sheet metal of the shank 28 is dished or dimpled at 38, to lock the shank 2S and insert 29 to each other against relative rotary movement.

The spindle 20, spaced inwardly from the end thereof, is provided with a set of keying borings 39 and 40, form ing sockets for the lobes herebelow described merging into a splined slot 41, running along the length of the spindle. Into this slot may be positioned the spindle key 42, which is formed at the outside end with an L- shaped head 43, and at its inner end with a T-shaped head 44, having a lobe 45 which may extend into either one of the borings 39 and 40 and a longer lobe 46, arranged to contact the throat 26 when the key is seated in the splined slot 41.

For the purposes of the present construction, it may be assumed that the latch casing 14 has been installed in the door frame stile with the inside escutcheon 21 and the outside escutcheon 21a and their respective thimbles assembled to each other. The order of assembly of the spindle 20 and knob may now be described.

The key 42 is projected into the slot 30 of the insert 29, with the L-shaped head 43 in contact with the wall 32 of the insert and the T-shaped head 44 projecting from or adjacent the end 35, as in Fig. 4.

With the key 42 resting against the side 33 of the slot in the insert 29, the spindle end 20 may then be inserted into the knob through the insert 29 until either aperture 39 or 40 is brought within the throat 26. It is projected through the throat, past the thimble 22, until the lobe end 46 passes the edges 22a of the thimble. In this position, a retaining ring 47 is employed to lock the key 42 in its position with the spindle.

The ring 47 is of a size snugly to pass the constricted mouth 22a of the thimble, but to be rotated within the enlarged portion 48 of the thimble with clearance. It has a slot 49 defined by the edges 5t), 59 of the branches 51. The bottom wall 52 of the ring 47 is formed with a groove 53 of a radius which, coupled with the entrance edges of the slot 49, snugly corresponds to the thickness of the key 42 and the spindle 24) with a snap or spring tension engagement, the groove 53 aso being useful to facilitate engagement by'a pointed tool for removal of the ring, if necessary.

With the ring 47 spanning the key 42 and the spindle 20 to hold the lobe 45 Within the boring 39 where this is selected alternatively with the boring 40 depending on the thickness of the door, the knob 28 and the spindle and key assembly carrying the key, is reversed its in movement to position the lobe 46 'into contact with the throat 26, thus sealing the ring 47 and the knob end within the spindle. In this position, the spindle 19 is projected through the latch, inside escutcheon 21a, and through the inside escutcheon thimble 22b. The inside end of the spindle a is screw threaded to screw threadedly engage the lever handle 28:: for adjustment thereof into engagement with the inside thimble 22b, whereupon the set screw 54 is driven home against the spindle end to lock the lever handle 28a and spindle into keying engagement.

The inside escutcheon 21a houses a spindle locking mechanism comprising the plate 55, having a spindle aperture 56 extending into a keying slot 57. The locking plate has its upper edge formed with a cutout 58. The lower end of the plate is provided with spring fingers 59 to either side of the tongue 60 which carries a push button 61, projected through the slot 62 of the outside face 63 of the escutcheon. It will be apparent that slidable movement of the plate 55 may shift the slot 57 into keying engagement with the spindle 19, tohold the spindle locked against rotation. The edges of the slide defining the slot 58 may then span the screw 64 to distribute the stress between spaced points and increase the locking force of the locking plate with relation to the ment in operating the spindle for retraction ofthe latch bolt, as will be readily understood.

It will be understood that by the construction described, a knob and spindle assembly is provided of compact nature so as not unduly to extend either of the inside or outside operating members comprising the knob and lever handle excessively to each side thereof,

yet securing adjustability which may be found desirable to accommodate the length of the spindle to doors of different thickness. This is accomplished without exposing screws or like members on the exterior face of the door when the door is locked, thereby preventing tampering with the lock by removal of the outside knob.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is: 7

1. In a door latch escutcheon assembly having a spindle for latch operation, a substantially tamper-proof exterior knob assembly including a shell knob member having a shank, an insert mounted in said shank including deformed means on said shank for holding said insert locked thereto, spindle and knob connecting means on said insert comprising a spindle receiving keyway within which said spindle may slide longitudinally, a splined slot on said spindle and a key carried by said splined dot, said key having extensions at opposite ends thereof of generally T- and L-shaped contour engaging said spindle and shank insert, respectively, and means on said shank insert for tiltably mounting said key for engagement along said spindle at predetermined positions of said spindle.

2. A knob and spindle connecting means for a door latch assembly in accordance with claim 1 wherein said escutcheon carries rotatable thimble means within which said shank is held, said thimble including means to hold said key against displacement.

3. A knob and spindle connecting means for a door latch assembly in accordance with claim 1 wherein said escutcheon carries rotatable thimble means within which said shank is held, said thimble including means to hold said key against displacement comprising a transversely slidable locking ring member.

4. In a door latch escutcheon assembly having a 5 spindle for latch operation a substantially temper-proof exterior knob assembly including a knob member, a shank extending from said knob member including bearing means thereon cooperating with mounting meansion said escutcheon rotatably. supporting said knob, a shank receiving thimble rotatably mounted on said escutcheon, spindle and knob connecting means for holding said shank in said thimble predeterminedly along said spindle, a spindle receiving splined slot on said shank, through which splined slot said spindle may slide longitudinally, 'a key on said spindle, said key comprising lobes of T-shaped and L- shaped contour on opposite ends of said key, spaced lobe receiving sockets comprising borings on'said spindle and means to selectively hold said key with a lobe from the T- r shaped end of the key Within one of said lobe receiving sockets, and clearance means on said shank for tiltably positioning said key along said spindle by means of one of said lobes.

5. In a door latch escutcheon assembly in accordance with claim 4 wherein said thimble includes a throat porsembly including a knob member, a shank extending from said knob member including bearing means thereon cooperating with mounting means on said escutcheon rotatably supporting said knob, a shank receiving thimble rotatably mounted on said escutcheon, spindle and knob connecting means for holding said shank in said thimble predeterminedly along said spindle, a spindle receiving splined slot on said shank, through which splined slot said spindle may slide longitudinally, a key on said spindle fitted within said splined slot on said spindle, means at one end of said key selectively to hold said key in engagement with said spindle along its length and having means at the opposite end of the key to hold said key and shank against slidable movement, longitudinally, tiltable clearance means on said shank for tiltably disengaging said key and spindle fromeach other, said thimble including a throat portion through which the said spindle extends J and having a contacting portion thereon to hold said key against tiltable displacement when said shank is seated gin said thimble.

References Cited in the filed this patent UNITED STATES PATENTS 419,894- Smith Jan. 21, 1890 826,187 McSpadden et al July 17,1906 923,233 Zwiller June 1, 1909 r 1,760,394 Best et al May 27, 1930' FOREIGN PATENTS 505,476 France May 7, 1920 

